Refractive index dispersion and Drude model Optics, Eugene Hecht, Chpt. 3.
HIGH AND LOW REFRACTIVE INDEX COATINGS FOR OPTICS
Transcript of HIGH AND LOW REFRACTIVE INDEX COATINGS FOR OPTICS
OPTICS FOR ALL-WEBINAR (APRIL 14, 2021)
HIGH AND LOW REFRACTIVE INDEX COATINGS FOR OPTICS
Jukka Perento, Inkron Oy
CONFIDENTIAL
TOPICS
Introduction
Portfolio for Optics
Nano-imprint lithography
Application and device level examples
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INKRON, SPECIALIST IN SILOXANE CHEMISTRY
INKRON – A NAGASE GROUP COMPANY
• R&D and manufacturing in Espoo, Finland. Opto-packaging team in Taiwan.
NAGASE AND NAGASE CHEMTEX
• Headquartered in Tokyo Japan. Related business manufacturing in Harima, Japan; Wuxi, China; and Ohio, USA.
• 7,200+ employees, global operations and annual turnover ca. US$8bn.
Japan
Taiwan
Finland
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LED PACKAGING
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• Die attach adhesives
• LED encapsulants
OPTICAL DEVICES
• Light management coatings
• Nano-imprint lithography, DOE
• High and low refractive index
TYPICAL MARKETS
PRINTED ELECTRONICS
• Printable inks
• Screen print, inkjet
• Structural adhesives
MATERIALS FOR OPTICS
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HIGH RI NIL COATINGS
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• RI range 1.55-1.9x
• Optically clear
• NIL processable
• Matching adhesion promoter
EDGE BLACKENING
• High RI (range 1.55-1.9x)
• High Optical density (OD)
• RI matched with the substrate
• Even 96 % reduction of backscatter (compared with “standard” black)
ESSENTIAL SOLUTIONS FOR AR, DOE AND OPTICS
LOW RI COATINGS
• Low RI, range 1.1-1.4
• Antireflection VIS/IR
• Gap filling, cladding layer
• Optically clear
IN SEARCH OF RIGHT REFRACTIVE INDEX COATING
n = 1.5 – 1.9x
Optical Coatings and NIL
n = 1.4 - 1.7
Optical Bonding
n = 1.1 - 1.4
Optical Coatings and Gap Fill
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HIGH RI NIL COATINGS’ OPTICAL PERFORMANCE
IOC n = 1.7 on glass*
IOC n = 1.8 on glass*
IOC n = 1.9 on glass*
IOC n = 1.8 on subst. corrected film transmission
IOC n = 1.9; Abbe = 17
IOC n = 1.8; Abbe = 19
IOC n = 1.7; Abbe = 36
*) Each measurement done with n matching Schott
RealView glass substrate
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CONFIDENTIAL 9
INKRON’S NIL FACILITY
NIL COATINGS’ IMPRINT PERFORMANCE
*Slanted grating master manufactured and provided by NIL Technology AsP.
• IOC with n = 1.7 – 1.92 shows great pattern fidelity in various stamp shapes and aspect ratios • Line/space gratings with linewidths down to 75nm with aspect ratio >3.5; Bi-directional 30° slanted
gratings with 400nm vertical height; Various pillar patterns (also non-spherical).
~ 50 nm residual layer
IOC 172 (n = 1.7) IOC 132 (n = 1.8) IOC 133 (n = 1.9)
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OPTICAL BLACK MATERIAL
1. Minimize the reflection at the edge of the glass by refractive index matching between the glass and optical black material.
2. Minimize light re-entering from the optical black coating to the high RI glass by having high absorbance black optical coating (high optical density, OD).
3. Minimized re-entering due to the scattering.
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OPTICAL BLACK AT LENS EDGE
96% decrease in reflectance when RI of the IOB coating is matched with the
glass wafer (n=1.9)
• Edge reflectance (%) drops from 10% to 1% with optical black coating • … and 96% (from 1% to 0.04%) with black coating n-value optimization• OD up to 5 with 25 um film thickness
Light reflectance on (n = 1.9) glass lens edge without and compared with different Inkron’s index of refraction optically black
coatings
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• Lens wafer to cover-lens stacking
LENS & HIGH/LOW-N STACKING
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Glass
GlassIAP-110 primer
IOC-133 RI 1.9
IBA-210 RI 1.4
Δn = 0.5 @589nm
Alternating:IOC n=2.05; 30nmIOC n=1.25; 130nm
• High – low refractive index layer stacking
Δn = 0.8 @589nm
GAP FILLING
APPLICATION EXAMPLES OF LOW RI COATINGS
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ANTIREFLECTION COATINGS
CLADDING LAYERS
• Particle free low RI, No haze or scatter
• Antireflection in VIS/IR
• Light guide optimization REFLECTED
PASSED
CLADDING
LIGHT- GUIDE
NO CLADDING
AR coating in visible area
AR coating in IR area
DEVICE LEVEL EXAMPLES
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3D SENSOR: TIME-OF-FLIGHT SENSOR
APPLICATION EXAMPLES
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• Sends a photon to the object, measures the return time of reflected light -> 3D depth map of the object
3D SENSOR: STRUCTURED LIGHT SENSOR
• Illuminates a known pattern on an object
• Pattern deformation used to calculate distance
AR GLASSES
• Waveguide (diffractive optics) for AR/XR glasses
DISPELIX AR GLASS DEMO
3D SENSORS
OTHER APPLICATIONS OF (DIFFRACTIVE) OPTICS